Laser devices have long been employed for skin ablation and/or hair removal and many other applications in the field of dermatology. For example, when the dermatological treatment is hair removal, it may be desired to heat and destroy a bulb of a hair follicle.
One of many examples of such laser devices is U.S. Pat. No. 6,511,475 to Altshuler et al., which describes methods and apparatus for dermatology treatment, such as for removal of unwanted hair, tattoos, port wine stains, spider veins or other vascular lesions, etc. The apparatus includes a handpiece that has three sections, an optical channel (i.e., a waveguide), a leading section which passes over the treatment area before the waveguide, and a trailing section which passes over the treatment area after the waveguide. Optical radiation is applied to the waveguide (or fiber bundle) or other suitable optical transmission components. Laser diodes or other suitable components may be in contact with the waveguide. The waveguide may be replaced with a lens or other suitable focusing or non-focusing optical transmission component (a waveguide, lens or other suitable focusing or non-focusing optical transmission component sometimes being collectively referred to hereinafter as an “optical channel”). The optical transmission component receives radiation from the radiation source utilized through a suitable optical transmission path.
Operation of the hair removal apparatus involves using continuous wave (CW) radiation, preheating the treatment volume, precooling, cooling during treatment and post-treatment cooling of the epidermis above the treatment volume, and various beam focusing techniques to reduce scattering and improve the delivery of the optical radiation.
The optical fiber bundles are stationary and are not part of the scanning apparatus.
U.S. Pat. No. 5,400,428 to Grace describes a method and apparatus for relatively moving energy across an array of optical fibers. The energy may be scanned across the fiber array. A dielectric mirror mounted on a galvanometer scanner is moved so as to cause successive pulses to irradiate different segments of the fiber optic array. As a result, each fiber receives radiation having sufficient flux while reducing the energy per pulse (or the CW equivalent). Rather than move the energy across the fiber array, the fiber array itself may be moved. One possible manner of movement is use of a piezo-electric stack.
It is important to note that although Grace contemplates moving the fiber array itself, the fiber array is moved as if it were a bundle of rigid sticks. In other words, the fibers are translated without any bending of individual fibers or groups of fibers.